B,C is correct. PIM (Protocol Independent Routing) amd MLD are the most common ones used in multicast. However OSPF uses multicast addressing for route flooding on a broadcast network link (224.0.0.5) More specifically it would be MOSPF.CDP is a propriety protocol from CISCO and I have not heard of it being used in multicasting.
B,C is correct. PIM (Protocol Independent Routing) amd MLD are the most common ones used in multicast. However OSPF uses multicast addressing for route flooding on a broadcast network link (224.0.0.5) More specifically it would be MOSPF.CDP is a propriety protocol from CISCO and I have not heard of it being used in multicasting.